How can I talk to him properly and make him understand my every explanation?

I have a best friend. We are not okay now because we had a misunderstanding. We know we can resolve the case because his heart is hard and his mind is closed to my explanations. He doesn’t talk to me anymore, and he doesn’t reply to my messages anymore.
I want to fix our misunderstanding. But how? How can I talk to him properly and make him understand my every explanation?